As long as you're writing somebody you know there's no need to put a return address as far as I know. I've also heard that if you put the sending address as the return address and mail it with no stamp it should go through as long as it's in the same city.
Yeah, but if they discover the stamp is fake, they might hassle your friend about it.
I tried reversing the address/return address and no stamp thing back in the 80's. It was in the same city, but they still figured it out somehow. The post lady knocked on my friend's door and talked to his mom about mail fraud. Then the mom yelled at me about it the next time I visited.
